The present invention relates to a process for preparing a thermosensitive fibrous structure, and more particularly to a process for preparing a thermosensitive fibrous structure which causes a fibrous substrate mainly composed of cellulosic fiber to exhaust microcapsules including a thermochromic material uniformly and almost completely from a bath, and if necessary, can improve color fastness to washing of the thermosensitivity.
Hitherto, there are proposed many processes for providing a fibrous structure with microcapsules including various functional materials. For example, in Japanese Unexamined Patent Publication No. 193979/1991, there is disclosed a method which comprises anionizing a keratin fiber by treating with an oxdizing agent and thereby causing the fiber to exhaust and to adsorb microcapsules including perfume cationized by polyamide epichlorohydrin. However, the method cannot be applied to a cellulosic fiber which does not have either a disulfide linkage or a peptide linkage. In Japanese Unexamined Patent Publication No. 174073/1991, there is described a method wherein a polyamide, a polyamine derivative or a lactam derivative which has polyoxyalkylene units without ionicity, and tannic acid and tartar emetic, a sulfonic acid compound or the like which is usually used as a fixing agent for a dye for a polyamide fiber are used to accelerate fixing of capsules to fibers when a polyamide fiber is uniformly provided with microcapsules including perfume. However, even if these fixing agents are applied to a cellulosic fiber, the microcapsules cannot be fixed uniformly. In a method of Japanese Unexamined Patent Publication No. 280080/1989, after water repellent treating with a cationic softening agent and silicone softening agent, a cotton plain weave fabric is padded with organosiloxane prepolymer and microcapsules including perfume, and then dried at 120.degree. C. for 2 minutes. However, even if this method is employed, the above mentioned capsules cannot be provided uniformly. Further, an object of these technique is to cause a fiber to shed fragrance by breaking microcapsules, for example, when the fiber is touched. Therefore, it is enough that the capsules fix uniformly when estimating with respect to a somewhat large area.
On the other hand, in case of providing a fibrous structure with microcapsules including a thermochromic material, considerably high uniformity is required. Therefore an object of this case cannot be achieved by the prior art as mentioned above.
An object of the present invention is to solve the above mentioned problem when a cellulosic fibrous substrate is provided with microcapsules including a thermochromic material.
This and the other objects of the present invention will become apparent from the description hereinafter.